Spring lock for steel tape ribbon



Oct. 21, 1952 R, c o so 2,614,769

SPRING LOCK FOR STEEL TAPE RIBBON Filed Aug. 17, 1950 I I! I! INVENTORQ'RA amen C-NICHOL sou ATTORNEYS,

Patented Oct. 21, 1952 SPRING LOCKFOR STEELTAPE RIBBON Ragnar C.Nicholson, Middletown; N. Y., assignor to Master Rule Manufacturing.(10., Inc.; Mid-. dletown, N. Y., a corporationrofr New York ApplicationAugust 17, 1950, Serial No. 179,957

Rulesof this type commonly consist of a-grad uated blade anda coilspring attached to the inner "end thereof for aiding in retraction ofthe blade-into a;housing. Asthe graduated blade is of spring steel it issubject to breakage. requiring replacement for this reason, or when theblade is worn out by defacement.

The graduated blade is in most cases detachablysecured at 'itsinner endto the outer end of the coil spring by some form of attaching device.II'IifOldBFtO' replace. the blade it isnecessary to fully withdraw itfrom the casing so 'thatthe end of the coil spring protrudes; Thisplaces the spring under maximum tension tending to withdraw it into thecasing. It follows, therefore, that any carelessness-in holding theprotruding end of the spring while the blade is be ing changed willresult in sudden retraction of the: spring end into the housing. Itfollows that the casing must then be taken: apart to regain control ofthe spring end.

The general object of this invention is to provide a locking device forholding the spring: end in"projected relation to the casing while-thedamaged blade is being replaced.

More specifically an object of this invention is to so construct the endof the spring and the exit sill of the housing so that the spring can beinterlocked therewith with its end protruding and thereby assure againstretraction while the broken or damaged blade is being replaced.

In the accompanying drawings,

Figure 1 is a side elevational View of a steel tape rule of the type towhich this invention is related, showing a portion of the housing brokenaway and a portion of the sill locked in elevation;

Figure 2 is a cross-sectional view taken on the line 2-2 of FigureFigure 3 is a perspective view of the housing at the tape openingshowing the end of the coil spring protruding therefrom;

Figure 4 is a similar view showing the protruding end of the spring heldin the sill lock;

Figure 5 is a cross-sectional view taken on the line 5-5 of Figure 1;

Figure 6 is a similar view taken on 6-6 of Figure 1; and

Figure 7 is a perspective view of the outer end of the graduated tape.

The housing consists of two substantially the line 6- Claims. (CI.24.2-84.9)

similar mating portions and 2 which are usually die-cast; They consistof walls of suitable configurationhaving right angle peripheral flangeswhich'meet in assembled relation tohold the walls so as 'to provide achamber for thecoil spring and graduated tape. These flanges maybeprovidedwith lugs 3 and (respectively, see Figure 5, which align whenthe housing portions are assembled. The lug-s 3 are provided with pins-5which seat in recesses-in the cooperating lugs so as to accuratelyposition the housing portion in assembled relation. The flanges at thebottom of the housing; portions are relatively thick to provide asill'member-fi as-showmin several of the figures, which liesbelowanopening 1 formed by cut-outs in the housing flanges. The housingportions are provided with aligned central posts which form a mandrel 8to which the inner end of the-coil spring-9 is attached. The housingportions are connected-together by means of a screw- H] which passesthrough one mandrel portion and'threadedlyengages the other. ofconstructionare quite common with some variation in detail in this artand involve no novelty as thus described.

The end of the coil spring 9 is provided with a pointed shoulderorT-shaped tip ll contiguous with a tapered portion l2 which convergestowards the tip portion. The tapered portion is contiguous to arectangular portion [3, which in turn is integral with a tail portionconsisting of a straightsided section ll forming a pair of shoulders 15providing an abutment at its point of union with portion [3. The tailportion of the spring includes another section It of uniform reducedwidth which is joined with the section 14 with a tapered portion H whichdivergestowards the tip end. The section I6 is joined with the mainspring 9 by means of a final tapered section l8 which converges from thenormal width of the spring 9 to the narrow straight sided section 16. Itis clear that the terminal end of the spring is integral with All ofthese features the tape l9 and the outer end of the coil spring 9, asclearly shown in Figure 2. The sill E; which forms a bottom side of thehousing opening 7 is provided with a dovetailed channel 22, which has awidth at the base equal to the width of the section i i of the spring.The housing portions l and 2 are provided with a pair of integrallyopposed pins 23 and 24 respectively which are tapered towards theirrounded ends, as clear- 1y shown in Figure 2. When the housing portionsareassembled these pins are aligned and spaced. The tip H of the springlies on top of the tape 19 when the tape is connected to the spring soas to project above the top face of the tape i9. This forms a projectionwhich might catch on the inner side of the opening 1, and as isclearfrom Figure 1, pins 23 and 2 are arranged so as to move the tape Hdownwardly to pass free- 137 through the opening 7.

In order to detach the blade from the spring the blade is fullywithdrawn from the housing, as well as the outer end of the spring untilits section IE3 reduced to a uniform width lies in the dovetailedchannel 22. The spring is then allowed to move back into the housinguntil the wider section Id lies in the base of the channel 22. Thetapered section ll tends to guide the spring so that it will thus seatin the channel. When thus seated the shoulders 15 engage the outer faceof the housing and hold the spring locked so that its end protrudes, asclearly shown in Figure 4. The graduated tip Ml can then be easilyreplaced without danger of the spring snapping back into the housing. Assoon as the new tape is attached the spring is pulled forward until isdisengages the dovetailed channel 22, whereupon it can move back intothe housing, retracting the graduated tape with it.

What is claimed is:

1. A steel tape rule comprising a housing having an opening and aguideway thereat, a coil spring mounted in said housing, a graduatedtape detachably secured at its inner end to the outer end of saidspring, and an abutment adjacent the outer end of said spring forengaging said housing at the opening when the spring lies in saidguideway, with its end protruding from the housing through said opening.

shoulders formed near the outer end of said spring.

4. In the combination of claim 1, said guideway comprising a dovetailedchannel formed in the housing at one side of said opening and saidabutment comprising shoulders formed near the outer end of said springby a section integral with said spring of a width equal to the width ofvthe channel at the bottom thereof.

5. In the combination of claim 1, said abutment comprising shouldersformed near the outer end of said spring by a section of less width thanthe normal width of the spring connecting sections of normal width andsaid guideway comprising a channel formed in said housing at the openingin which the portion of the spring of less width seats with theshoulders against the housing.

6. A steel tape rule comprising a housing having an opening, a coiledspring mounted in said housing, a graduated tape detachably secured atone end to the free end of said spring, and cooperating means on thehousing at the opening and on the free end of the spring provided forlocking engagement when the free end of the spring extends through theopening or" said housing to hold it in that position.

- RAGNAR C. NICHOLSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS- 7 Number Name Date 2,510,939 Carlson June 6, 1950

